Bonded mineral fiber products and process of preparing the same



July 22, 1952 M. c. ARMSTRONG ET AL BONDED MINERAL FIBER PRODUCTS AND PROCESS OF PREPARING THE SAME Filed Aug. 2, 1949 @weeg/4^ Patented July 22, 1952 BONDED MJNERA'I. FIBER PRODUCTS AND PROCESS oF PREPARING THE SAME Marshall C.'Armstrong, Hebron, ,and Eugene M.

Lockhart, Newark, Ohio, assignors to Owensy Corning Fiberglas Corporation, Toledo, Ohio, a

corporation of Delaware Application August'Z, 1949, Serial No. 108,086

. v y l1 This: invention relates vto integrated structures of glass wool'flbers employing: bonding agentsto impart greater self-sufficiency to the composite massand more 'rigidly to secure the fibers one to another vin l,the manufacture of insulation and structural boardproducts which vrange in 'density fromv 1/g'pound per cubic foot for insulation to 20 pounds per cubic foot forl board and the like.

Itis-an object of this inventionV to produce and toprovide a method for manufacturing bonded structures of glass wool 'fibers characterized by improved binder flow, binder distribution, and curing characteristics to enhance lthe processing technique, and improved moisture resistance and non-inflammability in the final product.

v`Other. objects and advantages of this invention will hereinafter appear, and for purposes of illustration vbut not of limitation, apparatus for manufacturingbonded glass wool fibers is shown in Figure t1 ofthe accompanying'drawing.

In a conventional system of manufacturing glass wool' fibers, molten glass I0 iiows in a plurality of streams I I from the nipple I2 of a bushingwI3 providedr in the base of a glass melting furnace J4.. As the molten glass streams II pass between cooperating converging blower relements I5: and I6,"high pressurel steam, air or gas, directedonto the molten glass streams at' a slight angle therewith, grip the glass streams and cause' their attenuation athigh speed into relativelyv small dimension fibers; This brieiiy describes the manufacture of staple glass fibers.

, The attenuated fibers are blown into a collecting chamber I1 of increasingv area which causes the deceleration of gaseous and fiber iiow with corresponding turbulent movement and uniform iiber distribution. Under such circumstances, the

bersla rain downslowly throughvthe collecting chamber rII and deposit in haphazard arrangement to form a layer upon a traveling foraminous belt I9 which may have a' suction box 2U arranged thereben'eath more substantially to hold the fibers in ftheirjdeposited position. Itwill fbe manifest thatfthe thickness of the deposited fibrous layer will depend chiefly upon the rate of feed of molten glass, the number of orifices in the fiber forming system, and -upon the rate of linearv travel of the normally endless collecting belt.

Unavoidably, there are times when molten glass, issuing from the melting furnace, is ,not attenus claims. (ci. 154-101) l i 2` which they might be exposed by the presence of the gob, no harmful effectszresult from such unavoidableinclusions.

But in most applications for glass wool fibers, a binder is'usedto secure the deposited fibers one to another, as in the manufacture of bonded Wool products wherein integrity and dimension are important characteristics. As shown in the drawing, binder may be incorporated with three fibers as they are rained down from above through the collecting chamber by injecting a spray 2I of the diluted binder composition from spray gunsr 22 f located in spaced-apart relation in the chamber. Alternatively, the binder maybe later supplied to the collected layer of fibers by a suitable dip or flow coat process.

r In the past, phenol formaldehyde type resins have constituted the principal bonding agent for' glass wool fibers. Suitable phenol formaldehyde resinous'materials are usually applied in an intermediate stage of polymeric growth and they are subsequently advanced to a cured stage upon activation by heat or catalyst, with or Without theA application of pressure for densication of the composite' mass into a board or molded insulation.

V.The phenol formaldehyde reaction is exothermic, that is, heat is given off by the reaction ofthe resinouslmaterial to an advanced stage of polymeric'growth. It is conceivable, then, that ated by the gaseous blast and, under'such cirselves inert'with respect to the temperatures to theiexothermic reaction will continue inthe vicinity of an accidentally included hot gob to a point far and beyond that which Was contemplated in the manufacturing process. that the surrounding glass wool fibers constitute excellent heat insulation, the heat of the gob andv the'heatA given off by the reaction will become cumulative within a confined area until such temperatures are attained as will cause thermal decomposition of the organic resin forming material 'to release various decomposition products, including vapors which may have an ignition temperature corresponding to the temperature of the surroundingmedium. When this condition is reached, the vapors will burst into flame andk the conflagration will spread tothe surrounding substances. The quiescent stage before actual ignitionis hereinafter referred to as punking It may lastffor a considerable length of time with the result'that the ignition of the entire shipment orload may occur in the Warehouse, and it has even occurred after the materialY has been dispatched in railroad cars for use at a distant station.

Punking and burning have occurred with binder compositions wherein the phenol formaldehyde In View of the fact' resin is admixed cr extended with as much as 50 per cent by other resinous materials, such as urea formaldehyde or the residue remaining after the separation of rened resin from the resinous extract of pine Wood (Vinsol) In the` attempt", toV eliminate Vities'e 'idang'erousi costly and 'embarrassing mishaps, adhesives have been formulated in Which urea formaldehyde resins replace all or the greater portion of theav n certain phasesimprovementa has been secured but binder com-positiensfbase'd?. 4.

phenolic resin.

on urea formaldehyde resin have many of the same and additional oldiectionable"characteris tics. For example, they do'not" jhave1a'djeeuate moisture resistance for all'usesof'-thebonded" fibrous material, and their curing rate is so rapid and'uncontrollable that it isk difficult: tofma'ke full use of the resinous material as a binding suitable adhesive film can still be formed, because unlike urea dicyandiamide formaldehyde resin alone is incapable of forming a lm or functioning as an adhesive to required extent.

Although phenol formaldehyde resinous materialse'aref preferred for gusea iii :combination with `dieyandia'lriicle formaldehyde; otherr related thermosetting phenol aldehyde resin forming V"substances may be used, such as the reaction products,.ofA an aldehyde with cresylic acids,

,fresercinol-,lY substituted phenols and the like.

These are usually applied to the glass fibers in antinterrnedi'atefistagec'of polymeric growth, gen- 'eral {referredto'asl the Water soluble A stage resinsf-,oreasan-advanced Water insoluble B f stage'resinwhich'isdispersible in Water or soluble v; inzsol'ventsfofitlre: type recognized in therart.

agent and to secure uniform distribution: This -1 is because the resinous material sets before full impregnation or distribution -.is achieved',:tha.t.'is;` before. it` has become: sufficiently: concentrated: at the juncture of the fibers to eiectivelyfsecurel the fibers one to another.V H

In accordance A. with 1 this: invention;tliere'.V ris,Vvv

provided a binder composition:characterized? by" its outstanding;resistancecito punlringp'fandicome bustion L While having# the t. desirablem-v character isticsvoffl fi'oW in partially" cured '.statei. coupled? ,Withl excellent 1 moisture; resistance. ini its cured'. condition. A binder:composition'embodying '.feai.- tures? of: this' invention constitutes; the f. product' resulting from= the' thermal' treatment .-o'f a; die; cyandiamideA formaldehydepresin: in partially. re:

Since dicyandiamide formaldehyde and A stageliphenolic resins are soluble in Water, a very acted, Water solublel stageV-v int admbrtu-rer.with^l a: 3*"

phenol formaldehyde resin advanced-toianii'nterev mediate; stage :of 1 polymeric: growth; thativ is: an

Arf orffB stage -.resin';i although; aaresin'in the Ai stage'. is` preferred. The. dic'yandiamide.`

formaldehyde resin may.' also beflin? .Br stage; :y

that 'l is;v in the -istagezwhere zit? is '.vvater@insoluble.- but?stilllincompletely,reacted:L

Thedesirable characteristics-With frespeet'ztoz flow, curing rate', and'lacln'of: attacknntthe'glass':

that* dicyandi'amide;formaldehydei readil'yg cures on' the alkaline* side.n This is :themost desirable` environment-fertile phenol@formaldehydeeresin,

particularly in.^ comparison Withffthesarcid'.condif tionsincidentgwith theuse of ureagformaldehydei f Thegbinder; formed; ofA dicyandiamid'aformafldef hydeV andaphenol. formaldelxydel hasarincreased Y moistureV resistancesuchfthat;l the; composition is :better adapted for use in.' combinations; with.: glass AWool -i'lbers fin* the manufacture,fof.bonded ,orf'molded glass? *Wool*A products. phenol 'formaldehyde fresirris.- presentiinfsubstane tial quantity, the` non-plungingl and non-inaml mabl-ef characteristics. fare effectively; maintained. f

The: dicyandiamida` formaldehydecomponent 1 maybe-presentinthe binder compositionfjin amounts .ranging-,from 25 vto 75 per centfsolidsabyf Weight Y depending. primarilyv .on the Weight. or

, density of@ the:ultimateeproduct and Athe-typeo-f; glass: fiber. For: example, `theamount-of dicyandia-mide formaldehyde. may"v go" to the: lower limit; of concentrationA` withY glass .f mats f having?- densitiesf'of` lessthan: 6Y pounds. perfcubic'. foot; butewhenig-reater densitiesv4 aredesired;I itis best torusef more than40 per centfby` Weight dicyandie amide-formaldehyde. Best all.around.useis.made of alcomposition-basedon equal parts by Weight-vdicyandiamide formaldehyde andphenol formale4 deliyde; resi-n.` ,Y The upperflimit-of` dicyandiamide formaldehyde concentration .isa tha-t at Which; a

resin... Y, l l l Y To give;y the; glass?, fibers l'ubricity; as:1 Well:.'asif.

protection againstrdestructioniordinarily;effected by; mutual abrasion or otherabrafsionrit isf-.prefere-n able- :also :to-fincorporate-inter ther treatingrcome positionfa lubricantvn of*1 thei types mihera'lzgo i sulfonated oils;- such: as: thosefdescribed jini;

Williams-3 and: Bone RatentsNosi; 25107528.41 and 2,083,132;l cationic-activer; amines; having." mores. thanrtenLcarbomatoms;- suclx'ras` thosezdescribed;

inthe. Sloan. :Patent No: 2,356,542 ;organo.-f"silicor1V i fluids and fccmpoundszandiWerner :complexzcome pounds; having more: than; eight: carboni atomsi infther'acido group coordinatedzwitlr'gthe .nuclear metallic. atom.-vv such as; described in: theizpatent'.- to;.--Iler'No. 2,'7'733040;` Itassufcient whenthef.

. amount:v of lubricant` constitutes oneri pen'centby Weight of.y the treating g composition;althougl'fas: much as twopercent or: moreamightbei-'used Application: of the' adhesivef compositionl is usually made-to .the staplegl-ass 'fibersz asi/they'arei y rained -rdown from above-onto the :'collectingebelti; J Thereafter. theI treated r layer ofi glass-1fibers;` the:

thickness-of'whiclrfmaysbefdeterminedmythgratei.. of `tra-,Velofftheficollecting belt, and? subsequentiy.l byy thevamount ofcompression applied Lto thesdea posited. layerduring the-.fouling cycle...y .is lgled;l through a drying 5 and fba-kingzoven; wherein ythe-f diluent of:T the, treating; compositionzis.drivenifoii andthefresiny which remains is y.convertedztozthefv cured' or :set condition.: The fibersz-'inlthee fabric l *i arefthus lsecured :one: to anotherfsorthatftheyreel tain; thei relationship :to..'\vh;ich they.' have been; formed duringfcure, asfby; corripressionito;proa` vide products of predeterminedidensityr. NateV uralglyi vthe;` strengtlr` ofl thee formed fabricAvv and 'f its:permanence ofzdimensioniwillvary: tosoima4 extentswithw the amountv of binderf presenti Eor;V lowf density' products: ongtlli'eforder of? lf2-tof 4f pounds `:percubicffoot; ther amount of resin may rangeafromf: 15E-tone perzrcent! by Weight.. UrrtuA 10. \fper ,centzbindert concentration: in tliet product'- is.1 'suitable for insulationv board ihaving` a-idensity between f6. 'andve10fp'ounds' per cubic' foot, and

ey following formulations are representative' of 'suitable-treating compositions for manufacturing bonded structures'of glass bers.

Example 1 l "A,. stage phenol formaldehyde 5 v%.v dicyandiamide formaldehyde 1%.-'ammonia based upontheamount ofviphenol formaldehyde resin 1% mineral oil Remainder water Example 2 3% phenol formaldehyde A stage resin 2.7% dicyandiamide formaldehyde 0.5% Vinsol 0.3% ammonia (28% solution in Water) 1% sulfonated mineral oil emulsion Remainder water Example 3 phenol formaldehyde "A stage resin dicyandiamide formaldehyde 1% ammonia in aqueous 28% solution 1% mineral oil Remainder water Example 4 2% phenol formaldehyde A stage resin 1% dicyandiamide formaldehyde 0.2% ammonia in aqueous 28% solution 1% dimethyl polysiloxane fluid 500 ctsk. viscosity (DC 200 oil) f Remainder water Formulations of the type 1, 2 and 4 may be applied from one or more spray guns arranged in the fiber collecting hood to inject a mist of the binder composition which becomes uniformly distributed With the bers as they collect upon the moving belt. Instead of supplying all or part of the binder composition to the bers as they are rained down from above, the binder composition may be incorporated with the layer of collected fibers by a dip, spray, or now-coat process Well known in the impregnating and coating arts.

The collected bers are then advanced into a curing oven maintained at a temperature calculated to drive off the diluent and cure the resinous binder. Not infrequently, the layer is given a slight compression for the purpose of densification and binder distribution. Upon cure of the resin the fibers are secured together to form a resilient product of substantially fixed dimension. Because of the dicyandiamide formaldehyde, the cure in the drying oven is sufficiently slow to permit drying and then cure under compression without fear of pre-cure at elevated temperatures such as might militate against the desirable-:migration ofthe bniderfto the rjunetures ofj the fibers where it is more able to fulll' the bind.-

ing action for vWhich its use vis intended. For

purposesV of illustration; "suitable drying and curing conditions for the described formulations include the rangeof 5 to .30 minutes at 250 to,A 400'.F; depending primarily upon the ratio of: dicyandiamide formaldehyderesin jto Vphenolic may be madein the formulation of the describedV materials and. their method ofA incorporation with glass fibers Without departing from the spirit of the invention,l especially as defined in thelap# pendedvclaims'.v

`D'We claim: f i V5' L1Ak fibrousy structure comprising 'glassfibers bonded into a composite mass with the product resulting from the advancement while on the bers of a mixture of 25 to 'l5 parts by Weight dicyandiamide formaldehyde in an intermediate stage of polymeric growth and 75 to 25 parts by Weight of a heat hardenable phenolic resin-forming material.

2. A bonded fibrous structure comprising haphazardly arranged glass fibers, and a bonding agent securing the fibers together, said bonding agent being the thermal product of dicyandiamide formaldehyde in an intermediate stage of polymeric growth in admixture with a heat hardenable phenol formaldehyde resin-forming material, the materials being present in the ratio of 25 to '75 parts by weight dicyandiamide formaldehyde to 75 to 25 parts by Weight phenol formaldehyde.

3. A fibrous structure comprising glass fibers bonded into a composite structure 0f predetermined density With the product of the thermal treatment of a mixture of partially reacted dicyandiamide formaldehyde and a heat hardenable phenol formaldehyde resin, the materials being present in the ratio of 25 to 75 parts by Weight dicyandiamide formaldehyde to 75 to 25 parts by weight phenol formaldehyde, and lubricated With about 1/2 to 2 per cent of an oleaginous lubricant incompatible with the said product.

4. A fibrous structure comprising glass bers bonded into an integral mass by the' product resulting from the conversion in the presence of alkaline catalyst to solid infusible state of a mixv ture of 25 to 75 parts by weight of partially reacted dicyandiamide formaldehyde and 75 to 25 parts by weight of a heat hardenable phenol formaldehyde resin and the residue remaining after the extraction of rosin from the resinous extract of pine wood and which may be present in amounts ranging up to equal proportions by weight of the phenol formaldehyde resin.

5. A fibrous structure comprising glass fibers, a bonding agent for imparting mass integrity to the fibers and consisting essentially of 2 to 30 per cent by Weight of the product of the thermal treatment of dicyandiamide formaldehyde with a heat hardenable phenol formaldehyde resin present in the ratio of 25 to 75 parts dicyandiamide formaldehyde and 75 to 25 per cent by Weight phenol formaldehyde, and less than 2 

1. A FIBROUS STRUCTURE COMPRISING GLASS FIBERS BONDED INTO A COMPOSITE MASS WITH THE PRODUCT RESULTING FROM THE ADVANCEMENT WHILE ON THE FIBERS OF A MIXTURE OF 25 TO 75 PARTS BY WEIGHT DICYANDIAMIDE FORMALDEHYDE IN AN INTERMEDIATE STAGE OF POLYMERIC GROWTH AND 75 TO 25 PARTS BY WEIGHT OF A HEAT HARDENABLE PHENOLIC RESIN-FORMING MATERIAL. 